Changes in the Past
by ThatOneGuyWhoWroteThatOneStory
Summary: Ever since he was betrayed, Percy has trained. Trained with the enemies. So when he goes back in time, what will he do differently? Will he even be a demigod? Or will he, perhaps, be something more? Evil!Percy. Eventual Percy/Bianca. M because I'm paranoid! On Hiatus


_**Disclaimer: I do not own PJO!**_

**Changes in the Past**

"Perseus."

Seventeen year old Perseus Achilles Jackson turned his dark eyes one of the few people he trusted. It had barely been three months since he was betrayed by those he once called friends and family. As his dark black eyes that radiated darkness stared at Tartarus, the Primordial suppressed a shiver. "Yes, Lord Tartarus?" Percy asked in a cold voice, having lost all joy and happiness in his life.

Tartarus waved his hand. He was approximately 6'4" tall, had red eyes that gleamed with insanity and chaotic blood red hair that flowed down to his shoulders. He wore an expensive all red silk suit that covered body. His skin was pale and scarred, as if he had seen many years of battle. When Percy had first met Tartarus, the man had made a bad impression, what with trying to kill him and… _her_, he thought viciously.

Tartarus sighed in exasperation, "How many more times do we have to tell you to not use titles while talking to us?"

"About three more," Percy responded, a flash of amusement showing in his cold, black eyes that simply glowed with incredible power.

"Fine. Don't call us by titles. Don't call us by titles. Don't call us by titles," Tartarus declared. "There, now stop calling me 'Lord Tartarus'!"

Percy smirked, "Lord Tartarus."

The Primordial of the Pit lowered his head in defeat before sighing, "I'll get you to simply call me Tartarus one day, Perseus Jackson. Just you wait."

"Good luck with that, Lord Tartarus," Percy remarked.

Tartarus rolled his eyes, "Moving on. We, Gaia, Erebus, Nyx, Chronos, Hydros, Chaos, and myself, have decided that it is time to grant you partial immortality. Your body has finally finished developing, meaning that granting you such immortality will not impair any growth you probably will not have."

Percy nodded and approached the Lord of the Pit, "Very well, Lord Tartarus."

As the two extremely different beings walked through Chaos' castle in the Void, Percy looked around, still amazed by the place, though, not letting it show on his face. He looked at Tartarus and asked a question that had been bothering him for a while, "Lord Tartarus, do you know if the Olympians, Aether, Hemera, Ourea, Pontus, Eros, Ananke, and Thalassa have knowledge of our plans?"

"Seeing as we're in the Void, and nobody but those Chaos allows may enter, I can say for a fact that our enemies do not know of our plans," Tartarus responded.

"Yes," Percy began, "but who else does Lord Chaos allow in the Void?"

"Other than you, Chronos, Erebus, Gaia, Nyx, Hydros, and myself, nobody."

"Ah, oh," Percy finished, relieved that so few beings had access to the Void, and by extension, their plans.

"Perseus, even if they _did _know our plans, you have no reason to be afraid. You do, after all, have all of our blessings. With more time to train you in how to use them, you will be perfectly capable of taking on the entire Olympian Council and emerge victorious without so much as a scratch," Tartarus scolded Percy for his doubts.

Percy smiled a true smile for the first time since that terrible day, a day that he would prefer to not think about. "So, is this your way of saying that I _will _get my revenge?"

Tartarus stared Percy straight in the eye and smirked, "Yes."

"Just checking."

**(Line Break)**

"Perseus, please, sit down. We have much to discuss," a man with a pale white body that had moving galaxy tattoos all over it. The man's eyes were raging infernos that always changed depending on his mood.  
"Very well, Lord Chaos," Percy answered.

The man now identified as Chaos frowned, "How many more times do we have to tell you to not use titles while talking to us?"

"About three more," Percy responded.

"Fine. Don―"

"Uh, Father," Tartarus interrupted, "don't do it, you'll just be wasting your breath. I would know," he finished, grumbling.

"Ok, then," Chaos stared at Percy, "as I was going to say, we have decided that your body has developed enough for you to gain partial immortality without any, err, _unpleasant_, side-effects."

"I'm ready when you are," Percy replied in an emotionless voice.

As the Primordials began their chant, they had a mental conversation with each other.

Erebus: _Is it just me or is the fact that he has almost no emotions a bad thing?_

Nyx: _It's just you._

Gaia: _Well, I wouldn't say that, Nyx. During the war, he was much more cheerful and enthusiastic._

Tartarus: _But, you seem to be forgetting the fact that that was _before _he was betrayed by them. Not that I'm complaining._

Chronos: _You better not be complaining. Do you have any idea how lucky we are that he was thrown into your pit… you… gah, you know what I mean._

Tartarus: _No, I don't._

Hydros: _Will you two stop being immature._

Tartarus and Chronos: _You're immature for thinking of it that way._

Chaos: _Why do I deal with you all?_

With that last thought, the ritual ended, and a brand new Perseus Achilles Jackson stepped forward.

"Oh, yes," Chaos began, "this war is definitely going to be fun to watch."

Percy smirked evilly.

**(Line Break)**

**Eight months later…**

"It's been three months, Death Breath! Get over it! He was a traitor! He deserves to rot in Tartarus!" Thalia shouted at her cousin.

"We didn't even give him a chance to defend himself, Thalia! What if he was innocent? What then, huh?!" Nico retorted.

"He wasn't innocent, so there's no need to think about it!" Thalia argued back.

This was what all of the demigods at Camp Half-Blood had been hearing for the past eleven months. Every time Nico came to Camp, he got into an argument with one of the campers about Percy. And every time, Nico stormed off into a shadow, going back to the Underworld.

_They all think that he would betray us?! _He would think bitterly, _We're the ones that betrayed him. I mean, really, how could they send him to Tartarus without even listening to him?! After all he had done to save Olympus, why would he turn around and betray it?! It's all my fault._ _If only I had been there with him, maybe then none of this would have ever happened._

"What proof do you have that Percy was a traitor?! Huh?!" He roared.

"What proof do you have that Percy was innocent?! Huh?! If you thought he was innocent, then why didn't you show up to defend him?!"

"Gah!" Nico rampaged to the nearest shadow. _No matter what it takes, Percy, I will find you, and I _will _stay by your side, no matter what, _was his last thought as he disappeared from sight.

**(Line Break)**

"Hm," Chaos mumbled, "interesting."

"What is interesting, Father?" Hydros asked.

It had been eight months since Percy had been made immortal. Eight _grueling _months of nonstop hard work and training. At the moment, Percy was currently off training with Nyx elsewhere in the Void.

"Apparently one of Perseus' friends believes in his innocence. I must admit, he sure is devoted to his friend. His last thought, in fact, was him promising that, as soon as he finds young Perseus, he'd stay by his side no matter what."

"Oh?" Gaia questioned. "And, just _which _friend of his promised that, Father?"

"I believe the boy's name is Nico Di Angelo," Chaos muttered, deep in thought.

"Perhaps we could convert him to our side," Erebus suggested.

"Yes, but that would more than likely be difficult," Chronos drawled.

"Uh," Tartarus spoke, "that might be easier than you think." At the questioning looks he was getting, Tartarus elaborated, "The boy just entered the Pit."

This caused a round of 'oh's to go around the room. "Well, then," Hydros began, "let's go get him."

As everybody was moving to get up, Chaos raised his hand, stopping them all. "No. Not yet." He looked at Erebus, "Go get Perseus and your wife, they deserve to be a part of this." Once Erebus left, Chaos continued, "While we wait, do any of you know of any others that believe in his innocence? Immortal or mortal, every person that believes in his innocence is a potential ally of ours."

"Well," Tartarus began uncomfortably, "I _have _been getting pestered by Hades. He has requested multiple times for Percy's release. He said, 'Unlike most of my family, I'm not stupid.' And, I'm kind of inclined to agree with him."

"Interesting," Chaos muttered.

"I, also, have noticed somebody who believes in Percy's innocence," Chronos spoke.

"Who?"

"Hestia," he smiled.

"Ah, yes, Hestia. I've always been fond of her," Chaos mentioned, getting nods of agreement from all of the other gods present.

Suddenly, Percy, Nyx, and Erebus arrived in the middle of the throne room. Due to the immortality ritual and his training, Percy was now 6'1" and weighed around 200 lbs. All of it muscle. If you saw Percy with his shirt off, you'd see an extremely tight eight pack. His hair now ran down to his shoulder blades and his blackened eyes gleamed with danger. Any who looked into his eyes would immediately know that the kind and happy-go-lucky Percy Jackson was long gone. Replaced by a cold being that couldn't even be called human. Just under his shoulder blades, two black wings with blood red stripes rested. The wings had been a gift from Tartarus after he had mastered all of Tartarus' powers. While he loved the wings, he was also happy that he could make them disappear.

In Percy's left hand was his sword, Shadowbane. The sword was made completely of shadows, and constantly shifted around, never staying still. Nobody but Nyx, Erebus, Chaos, and he could wield the blade, as it required Primordial-level control over shadows to even hold. In his right hand was a similar, yet completely different, blade. Hellbringer. Hellbringer had been another gift from Tartarus after Percy had finished his training with the Primordial. The blade was made with pure Chromium ore and water from the Delta of Despair, the place where the five rivers of the Underworld meet. Licking on the edges of the deadly blade was Hellfire. Hellfire was extremely volatile, but when used right, could make an extremely dangerous weapon. The only noise in the room upon Percy's arrival was the sound of the Hellfire licking at the sword.

"You called, Chaos?" he asked coldly as his wings flapped impatiently. Over the past eight months, the Primordials had _finally _gotten Percy to stop calling them 'Lord' or 'Lady', depending on the gender.

"Yes. I have learned something that you might like to know, Perseus," Chaos said seriously.

"Oh? And what, per se, is that?" Percy continued in a mocking voice. Now, one may be wondering why the Primordials don't kill him for his lack of respect. The answer, would be the facts that they needed him and that he has earned their respect, meaning that they will accept his criticism.

"Nico Di Angelo entered Tartarus not long ago," Chaos responded nonchalantly, smirking as he saw Percy tense slightly.

"Really?" he ground out. "And, _what_, exactly, is he doing there?"

"Looking for you," the creator of the universe answered.

"Why?"

"Because he believes in your innocence and wants to do whatever it takes for you to forgive him for not being there when you needed him."

Percy took on a pensive look, "And you believe that we can use this to our advantage and have him join us, correct?"

"More or less," Chaos replied.

"Fine. What do you want me to do, go and get him?"

"Yes."

"Ok," Percy began sarcastically, "so let me get this straight. You want _me_, the slayer of over two-thirds of all monsters, to go to _Tartarus_, the home of said monsters, and bring Nico here."

"Well," Chaos answered uncomfortably, resulting the other Primordials snigger at how their _all mighty _Father was scared of a seventeen year old, "when you say it like _that_ it sounds bad."

"That's because it is," Percy said with finality, causing all of the gathered Primordials, bar Chaos, to laugh at the fact that the creator of the universe had just been shown up by, once again, a seventeen year old **(A/N: technically 18 at this point)**.

"Fine," Chaos muttered, finally regaining his wits. He turned and looked at Tartarus, "Go and get the boy." Tartarus nodded and disappeared in a flash of Hellfire.

**(Line Break)**

**Meanwhile in Tartarus…**

Nico Di Angelo hiked through the Pit along the banks of the Phlegethon River, thoroughly exhausted. He had hardly been in Tartarus for an hour and he was already attacked nine different times. So, this combined with his exhaustion, explains why he didn't even react as his shoulder was grabbed from behind, before he disappeared in an eruption of Hellfire.

**(Line Break)**

**Back to the Void…**

Not even a minute after Tartarus left, he appeared in the middle of the throne room, holding onto a weak, tired, and alarmed looking Nico Di Angelo. Nico slowly tried to grab his sword so he could defend himself, but he was too slow, as Percy moved at superhuman speeds and knocked it away.

"Now, now, now," Percy scolded, "is that any way to greet an old friend?"

Nico looked at Percy and his eyes widened, his mouth opened and closed in shock. Only several minutes later was he able to cough out, "Percy?" Then the world went black for Nico Di Angelo.

"Huh," Percy grunted, "I think I broke him."

Erebus snorted in response, "Ya think?"

**(Line Break)**

**Two hours later…**

"So," Nico began, "let me get this straight. You and the Primordials have teamed up to destroy Olympus and you plan to do so by having Lord Chaos and Lord Chronos work together to turn back time, but instead of being a son of Poseidon, you'd be a son of Gaia, Chronos, Erebus, Nyx, Hydros, Tartarus, and Chaos. You would then grow up here, completely separated from the Olympians and their influence, and continue training and honing your skills. Then, during the Titan War, you would be wandering around America just wreaking havoc for both the Titans and the Olympians? And finally, after the Giant War, you and the Primordials would declare war on Olympus and destroy them with ease?"

"That's correct," Percy nodded.

"What I don't get is why they had to give you partial immortality," Nico finished.

"Ah, that," Chaos jumped in. "We gave him partial immortality because that was the only way for him to go back in time and keep the knowledge he has now. It will also allow him to keep the blessings we have bestowed upon him, after the time jump."

"Ok," Nico added slowly. "Who all is going to remember what's happened?"

"Well, us, obviously," Hydros began, "then there's Percy, the Fates, who have sworn themselves to neutrality, and, if you choose so, yourself. You will, however, have to stay in the Lotus Hotel and Casino until the time is right. When the time is right, Percy will break you and your sister out and take you to your father as an act of good will. We believe that if he does this, your father would be more willing to join us."

Nico thought it over and nodded, "Alright, I'm in. When is this all going to happen? And how would we continue aging, seeing as we would both be immortal?"

"Immediately after we give you partial immortality. As to answer your second question, you will lose your partial immortality immediately after we finish going back in time," Chaos answered.

"I'm still confused, but, whatever. So when's that going to happen?" the son of Hades asked.

"Right now."

With that sentence, the Primordials repeated the process they had done with Percy and proceeded to make Nico partially immortal **(A/N: When talking about Nico, Percy, and others who get partial immortality, I'm just going to call it immortality for convenience sake.)**.

**(Line Break)**

**Eight years earlier… (A/N: Bear with me, the time skips are almost finished.)**

"Why'd you only turn time back by eight years instead of all eighteen?" a ten year old Perseus Jackson asked his parents as of a few seconds ago.

"Because, Perseus," Chaos began, "if we turned time back by eighteen years, then you would be no more and the blubbering infant."

"Oh yeah," Percy said. "So, when _is _the right time for me to go and get Nico and Bianca?"

"During the quest for the Master Bolt, that way, you can cause trouble _and _save your friends," Tartarus responded.

"Ok."

"Now, let's start training you… again," Chaos trailed off.

**(Line Break)**

**Two years later… (A/N: Finally the last multi-year time skip.)**

"Perseus," Tartarus called, "it's time."

"Yes!" Percy fist pumped before disappearing into the shadows to get his stuff from his room. Tartarus sighed and shook his head, amused by the boy's antics. He also mused over the large emotional change Percy had undergone since they had all gone back in time. But, deciding that it wasn't really important, Tartarus disappeared in a flash of Hellfire, only to reappear in the Void's Throne Room. He strode to his throne and sat down, patiently waiting for Percy to return so they could finally do something other than train Percy.

Percy's extra two years of training made a huge difference. While before, he sucked at archery, he could now get a bull's-eye every time. His sword skills had continued to improve. In fact, they improved to the point that he could fight both Tartarus and Erebus at once and hold his own for at least an hour, but whenever he's fighting one versus one, Percy dominates the fight. His training with his powers had all improved drastically. He could now use the liquid in a person's body and blood to control them. Now, having trained with Chaos on his powers granted by the Creator, he could take on three Primordials at once by using their own elements and come out victorious with only a few scratches. This irritated Tartarus and Erebus, who were both peeved by the fact that Percy could beat them. Percy's favorite bit of training, however, had to be learning how to open portals for easy travel. The day he learned how to do it, every Primordial in the Void watched with amusement as he opened portals to a spot not even three feet away.

Soon enough, Percy walked out of a portal that had just formed in the middle of the room. He was grinning maniacally, seemingly happy to finally do something other than train. He was wearing a black leather jacket with a matching pair of gloves, and a pair of dark shades to complete the 'badass' look. His hair flowed down to his shoulders and his black wings with blood red stripes flapped eagerly.

"Alright, Perseus," Chaos began, rising from his throne, "it is time for you to go to Earth and cause as much trouble as you can. During that time, you should also free Hades' children and secure him as an ally. Do not, however, that while we expect you to cause trouble, we don't want you to cause the quest to fail. Remember, the quest _must _succeed in order for the events that lead to the Titan War begin. Also, keep in mind that the _new _child of the prophecy is still the son of Sally Jackson and Poseidon. Apparently, the Fates had to replace you so balance could be restored or something like that."

Percy nodded, then asked impatiently, "Can I go now?"

"Yes, Perseus, you m― Why do I even bother saying anything beyond 'yes'," he grumbled.

**(Line Break)**

Percy emerged from his personal portal behind a tree out of sight at Camp Half-Blood, and watched as his replacement entered the Big House in order to get the prophecy for the quest. Percy's replacement looked almost like an identical copy of what Percy looked like before he joined the Primordials. He had messy black hair and sea-green eyes. He was wearing the orange Camp Half-Blood t-shirt, and even stood at the exact same height as Percy once did.

Percy broke out of his musings and started to wait for his replacement to begin his quest. As soon as the quest members left, he planned to go and get Nico and Bianca, knowing that nothing interesting was going to happen anytime soon. Aside from the Furies and Medusa, of course.

Eventually, the boy came out of the Big House with a pale complexion, with Annabitch and Grover walking behind him. Once he finished watching the three leave the camp, Percy opened up a portal and walked into it.

**(Line Break)**

**Lotus Hotel and Casino**

Percy walked out of the portal behind a dumpster outside the Casino. He held his breath, having not realized just _how _bad it would smell, and rushed to the nearest entrance. He then strode up to the front desk, looked the female receptionist straight in the eye, and said in a cold voice, "What room are Nico and Bianca Di Angelo in?"

The receptionist looked a little put off by his cold attitude, but shook it off. Before she could utter a retort, Percy directed a small fraction of his hidden aura at the woman, causing her to immediately shiver and go deathly pale. She looked into Percy's eyes with something akin to fear and stuttered out quietly, "P-penthouse su-suite #1. I-it's on the to-top fl-floor."

Percy nodded at her before hiding his aura once again and walked to the elevator. He slammed the button for the top floor and waited calmly as terrible elevator music played in the background. After a few minutes, the elevator dinged and the door slid open, revealing three doors. One to his left, one to his right, and one right in front of him. He scanned the three doors and strode over to the one that read 'Penthouse suite #1'. He knocked three times on the door and waited for Bianca or Nico to answer. After a few moments, the door opened revealing the form of Bianca Di Angelo. "Good evening, ma'am," he said respectfully, causing Bianca to blush.

"U-uh, h-hi. Can I help you with something?" she asked. Percy couldn't help but notice for the first time how beautiful Bianca truly was. He never had time to really appreciate her good looks before she died, seeing as he was so love-struck over Annabeth. _I was foolish_, he thought bitterly, but outwardly smiled.

"Actually, yes. I would like to ta―"

"Bianca! Who is it?" Nico shouted, rushing into the room. As he caught sight of Percy, he went wide-eyed before grinning and tackling him in a man hug. "Percy! 'Bout damn time!"

"Uh, Nico, do you know him?" Bianca asked her brother.

"Huh? Oh, yeah, Bianca, this is Percy. Percy here is going to take us to dad," he told her.

"Nico, how many times do I have to tell you? Dad's dead?"

At that last comment, Percy snickered. Upon seeing the incredulous look he was getting from Bianca, he said, "Well, it's ironic that you say that, considering just _who _your dad is."

Bianca raised an eyebrow, "Oh? And who might that be?"

"Hades," he finished, dead serious **(no pun intended)**. "And now," he continued, "I'm going to take you to him."

He quickly snatched Nico's arm, who grabbed Bianca's, just in time to disappear with the two boys via shadows.

**(Line Break)**

**The Underworld…**

Hades was sitting quietly in his study, thinking about his current situation. _Should I send the Furies to retrieve my Helm from the boy, or should I wait for the boy to bring my Helm to me?_

He was soon broken out of his thoughts when all of a sudden, the shadows in the room thickened. He quickly hopped up and tried his best to rein in control of the shadows, but whoever was controlling them was too strong. Just as the shadows were about to cover Hades, they stopped. Hades looked around bemused, wondering what had happened, when he heard a voice behind him.

"Lord Hades," it said respectfully.

He spun around faster than the eye could see and prepared to attack the owner of the voice, only to stop in shock as he was that the speaker only looked to be twelve at most. He then peered behind the shoulders of the stranger, and his hit the floor, seeing that the boy had his two children.

After a few minutes, Percy cleared his throat and said, "You should close your mouth, or you'll let flies in." That broke him from his daze and he stepped forward and grabbed his two children in a hug. After a quick hug, he pulled back and looked at his two children. He frowned upon seeing Bianca's confused face.

"Who are you?" she asked.

He took a deep breath and spoke, "Bianca, I am your father, Hades."


End file.
